Per PC Mag, an Australian regional airline had to extinguish a glowing red iPhone 4 that was emitting “dense smoke” on an airplane have sparked concerns over the handset’s battery safety.

Regional Express (REX), the country’s largest independent regional airline, said last Friday that a passenger’s iPhone was emitting a “red glow” and smoke on a flight from Lismore to Sydney. A flight attendant extinguished the smoking smartphone and no one was injured during the incident.

Judging by the model number of the device, the handset in question is the GSM version of the iPhone 4.

The Australian Transport Safety Bureau and the Civil Aviation Safety Authority have both been notified of the matter. Though the mishap may prompt an investigation by officials, it does appear to be a relatively isolated occurrence.

The issue does, however, come on the heels of an Apple replacement program for the first-generation iPod nano due to potential battery overheating issues. After first rolling out replacement offers in select countries, Apple initiated the program worldwide earlier this month, noting that the problem is “very rare,” though the likelihood of overheating does increase over time.

In April, the U.S. House of Representatives passed a bill exempting lithium batteries used in consumer electronics from proposed limitations that would classify the batteries as hazardous materials. According to an analysis commissioned by the Rechargeable Battery Association, the limitations would have cost electronics makers US$1.13 billion alone in the first year.

One of the biggest consumer electronic battery scares in recent years occurred in 2006. Sony recalled 9.6 million lithium-ion batteries that year after microscopic metal particles were detected inside the batteries. The incident affected Apple, which had to recall 1.8 million iBook and PowerBook G4 batteries. Sony had also supplied the defective batteries to Dell, Fujitsu, Gateway and Toshiba.